Over the past decade, pediatric palliative care has emerged as a new subspecialty, as palliative care programs are being established at many children's hospitals. Nonetheless, optimal care for children with life-limiting and terminal conditions continues to be hindered by an inadequate evidence base regarding the effectiveness and safety of medications used to manage patients' pain and symptoms. The dearth of information and evidence of effectiveness and safety hampers the development of pediatric palliative care, both in terms of improving the quality of clinical practice and in terms of motivating the development of hospital-based programs and teams dedicated to assuring access for all pediatric patients potentially in need of palliative care to highest quality clinical services. We therefore propose to study the Comparative Effectiveness and Safety of Hospital-Based Pediatric Palliative Care (PA-09-070, AHRQ (RO1), Comparative Effectiveness Portfolio). We will use the vast and detailed Pediatric Health Information System and Premier hospital datasets, which record patients' receipt of doses of medications in detail, to study the use, effectiveness, and safety of palliative care-related pharmaceuticals (PCRPs) received by pediatric patients with life-threatening complex chronic conditions in 2006-2008. PCRPs represent drugs that are used to treat patient symptoms and ameliorate any suffering. Seven PRCP classes of drugs have been identified by this group. Specifically aims are to: 1. Determine the overall proportions and rates of use of PCRPs and rates of possible drug-drug interactions among hospitalized children with life-threatening complex chronic conditions; 2. Analyze variation among hospitals in the usage of PCRPs in the treatment of these hospitalized children; 3. Compare PCRP-treatment-associated outcomes and adverse events between matched sets of hospitalized children with life-threatening complex chronic conditions, measuring the differences in outcomes and adverse events among patients who did and who did not receive PCRPs in 8 specific clinical scenarios. The multi-disciplinary research team of investigators will benefit from the guidance of a panel of expert consultants, including bereaved parents and leading national pediatric palliative care practitioners and researchers. The resulting findings and information will shape and motivate future quality of care metrics, clinical care guidelines, and the design and conduct of clinical palliative care trials.